how to release the disk space taken by 'download-as-zip'

I'm using alfresco community edition 5.2.g, which has the download-as-zip api. ( alfresco/api/-default-/public/alfresco/versions/1/downloads/ ). Each time the API is called, alfresco seems to create a temporary node in data space. When there are tens of user use this function, my server's disk space quickly runs out.

Finally, I have to disable this function. To me, Alfresco keep those temporary nodes and won't delete it.

I wonder if Alfresco is able to free the space taken by the 'temporary' nodes. I think there should be a way to config the life time of the temporary data. Please if you can help.